After Rihanna sipped D’Usse shots with Jay-Z at the opening of his 40/40 club at the Barclays Center, the singer headed back to Manhattan to wish former “106 & Park” co-host Rocsi Diaz bon voyage. Diaz held her goodbye-to-New York party at Greenhouse in SoHo on Thursday night, as the former VJ moves to LA to pursue acting. As a parting gift, two burly men dressed as cops brought out a cake and presented it to her. Then they took off their shirts and shimmied for guests, including Tika Sumpter, Dwight Freeney and Adam Rodriguez. Diaz and her co-host, Terrence J, who just accepted a job as co-anchor of E! News, were both given a send-off on the BET show Friday night.